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LOBELIA

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Originally appearing in Volume V16, Page 837 of the 1911 Encyclopedia Britannica.
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LOBELIA , the typical genus of the tribe Lobelieae, of the See also:

order Campanulaceae, named after See also:Matthias de Lobel, a native of See also:Lille, botanist and physician to See also:James I. It See also:numbers about two See also:hundred See also:species, natives of nearly all the temperate and warmer regions of the See also:world, excepting central and eastern See also:Europe as well as western See also:Asia. They are See also:annual or perennial herbs or under-shrubs, rarely shrubby; remarkable arborescent forms are the See also:tree-lobelias found at high elevations on the mountains of tropical See also:Africa. Two species are See also:British, L. Dortmanna (named by See also:Linnaeus after Dortmann, a Dutch druggist), which occurs in gravelly See also:mountain lakes ; and L. ureter, which is only found on heaths, &c., in See also:Dorset and See also:Cornwall. The genus is distinguished from See also:Campanula by the irregular See also:corona and completely See also:united anthers, and by the excessive acridity of the milky juice. The species earliest described and figured appears to be L. cardinalis, under the name See also:Trachelium americanum sive cardinalis planta, " the See also:rich See also:crimson See also:cardinal's See also:flower "; See also:Parkinson (Paradisus, 1629, p. 357) says, " it groweth neere the riuer of See also:Canada, where the See also:French See also:plantation in See also:America is seated." It is a native of the eastern United States. This and several other species are in cultivation as ornamental See also:garden See also:plants, e.g. the See also:dwarf See also:blue L. Erinus, from the Cape, which, with its numerous varieties, forms a See also:familiar bedding plant. L. splendens and L. fzalgens, growing from 1 to 2 ft. high, from See also:Mexico, have See also:scarlet See also:flowers; L.

Pupa, a Chilean perennial 6 to 8 ft. high, has reddish or scarlet flowers; L. tenuior with blue flowers is a See also:

recent acquisition to the greenhouse See also:section, while L. amaena, from See also:North America, as well as L. syphilitica and its hybrids, from See also:Virginia, have also blue flowers. The last-named was introduced in 1665. The hybrids raised by See also:crossing cardinalis, fulgens, splendens and syphilitica, constitute a See also:fine See also:group of fairly See also:hardy and showy garden plants. See also:Queen See also:Victoria is a well-known variety, but there are now many others. The Lobelia is familiar in gardens under two very different forms, that of the dwarf-tufted plants used for summer bedding, and that of the tall showy perennials. Of the former the best type is L. Erinus, growing from 4 to 6 in. high, with many slender stems, bearing through a See also:long See also:period a profusion of small but See also:bright blue two-lipped flowers. The variety speciosa offers the best See also:strain of the dwarf lobelias; but the varieties are being constantly superseded by new sorts. A See also:good variety will reproduce itself sufficiently true from See also:seed for See also:ordinary flower See also:borders, but to secure exact uniformity it is necessary to propagate from cuttings. The herbaceous lobelias, of which L. fulgens may be taken as the type, may be called hardy except in so far as they suffer from See also:damp in See also:winter; they throw up a See also:series of See also:short rosette-like suckers See also:round the See also:base of the old flowering See also:stem, and these sometimes, despite all the care taken of them, rot off during winter. The roots should either be taken up in autumn, and planted closely See also:side by side in boxes of dry See also:earth or ashes, these being set for the See also:time they are dormant either in a See also:cold See also:frame or in any See also:airy See also:place in the See also:green-See also:house; or they may be See also:left in the ground, in which See also:case a See also:brick or two should be put beside the plants, some See also:coal ashes being first placed round them, and slates to protect the plants being laid over the bricks, one end resting on the earth beyond. About See also:February they should be placed in a warm See also:pit, and after a few days shaken out and the suckers parted, and potted singly into small pots of See also:light rich earth.

After being kept in the forcing pit until well established, they should be moved to a more airy greenhouse pit, and eventually to atcold frame preparatory to planting out. In the more favoured parts of the United See also:

Kingdom it is unnecessary to go to this trouble, as the plants are perfectly hardy; even in the suburbs of See also:London they live for several years without See also:protection except in very severe winters. They should have a loamy See also:soil, well enriched with manure; and require copious waterings when they start into See also:free growth. They may be raised from seeds, which, being very fine, require to be sown carefully; but they do not flower usually till the second See also:year unless hy are sown very See also:early in See also:heat. I'he species Lobelia inflata, the " See also:Indian See also:tobacco " of North America, is used in See also:medicine, the entire See also:herb, dried and in flower, being employed. The species derives its specific name from its characteristic inflated capsules. It is somewhat irritant to the nostrils, and is possessed of a burning, acrid See also:taste. The See also:chief constituent is a volatile liquid See also:alkaloid (cf. See also:nicotine) named lobeline, which occurs to the extent of about 3o%. This is a very pungent See also:body, with a tobacco-like odour. It occurs in See also:combination with lobelic See also:acid and forms solid crystalline salts. The single preparation of this plant in the British Pharmacopeia is the Tinctura Lobeliae Ethereae, composed of five parts of See also:spirits of See also:ether to one of lobelia. The dose is 5 to 15 minims.

The ether is employed in order to add to the efficacy of the See also:

drug in See also:asthma, but a See also:simple alcoholic See also:tincture would be really preferable. Lobelia has certain pharmacological resemblances to tobacco. It has no See also:action upon the unbroken skin, but may be absorbed by it under suitable conditions. Taken internally in small doses, e.g. 5 minims of the tincture, it stimulates the peristaltic movements of the coecum and See also:colon. In large doses it is a powerful gastrointestinal irritant, closely resembling tobacco, and causing giddiness, headache, See also:nausea, vomiting, purging and extreme prostration, with clammy sweats and faltering rapid See also:pulse. Its action on the circulation is very decided. The cardiac terminals of the vagus nerves are paralysed, the pulse being thus accelerated by loss of the normal inhibitory See also:influence, and the See also:blood-vessels being relaxed owing to paresis of the vasomotor centre. The blood-pressure thus falls very markedly. The See also:respiratory centre is similarly depressed, See also:death en-suing from this action. Lobelia is thus a typical respiratory See also:poison. In less than toxic doses the motor terminals of the vagi in the bronchi and bronchioles are paralysed, thus causing relaxation of the bronchial muscles.

It is doubtful whether lobelia affects the cerebrum directly. It is excreted by the kidneys and the skin, both of which it stimulates in its passage. In See also:

general terms the drug may be said to stimulate non-striped See also:muscular See also:fibres in small, and paralyse them in toxic doses. Five minims of the tincture may be usefully prescribed to be taken See also:night and See also:morning in chronic See also:constipation due to inertia of the See also:lower See also:part of the alimentary See also:canal. In spasmodic (neurotic) asthma, and also in See also:bronchitis accompanied by asthmatic spasm of the bronchioles, the tincture may be given in comparatively large doses (e.g. one drachm) every fifteen minutes until nausea is produced. Thereafter, whether successful or not in relieving the spasm, the See also:administration of the drug must be stopped.

End of Article: LOBELIA

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